Four cases of cystic hydatid disease treated with albendazole are described. The first patient had previously undergone surgical treatment with only partial removal of her hepatic cysts. The size of the remaining cyst resulted remarkably reduced after three courses of the drug. The second patient had recurrent hydatid disease involving the lumbar spine. After therapy, an evident diminution in the size of the cyst was detected. Two patients (one with a partially calcified cyst of the liver, the other one with multiple pulmonary lesions) did not show any objective evidence of improvement. Failures were probably due to the presence of calcified or thick-walled cysts. In all the patients, neither side-effects were observed, nor recurrences were noted during a 2 years' follow-up. In cystic hydatid disease, whenever radical surgical procedures are impracticable, albendazole treatment can achieve significant clinical results.